The present invention relates to phosphates of amines having at least one terminal imide cycle, a process for the preparation of these compounds and their uses as additives permitting, during the cooling of the middle distillates of hydrocarbons containing paraffins (fuel oils, gas oils) the slowing down of the sedimentation of these paraffins.
In winter, deposits may form on tanks containing non-dewaxed petroleum products such as middle distillates and in particular domestic fuels and gas oils. These deposits are due to the crystallization and sedimentation of paraffins, which become insoluble when the temperature drops below the cloud point (in France -5.degree. C. for gas oils and +2.degree. C. for domestic fuels).
The lower the temperature the greater the crystallization. It consists of the joining of paraffin molecules along their major axis, which leads to a growth in the form of very fine platelets, which can agglomerate with one another. The sedimentation of these paraffin crystals is dependent on the one hand on their size and their morphology, which are a function of the composition of the fraction and the cooling rate, and on the other of the fluidity of the medium.
Sedimentation has a prejudicial effect both in storage containers and in vehicle tanks, because the orifice of the suction pipes is located in the bottom of the tanks, where the product is concentrated in solid paraffin form. This product sucked in at the start of pumping may rapidly clog the filters of the supply circuit, which hold back the crystallized paraffins.